The effective decrease in bb height per the figures below would be insignificant:
2110/3.14=672 diam 2094/3.14=667 diam 672-667=5 mm difference in diam 3 mm/2 = 2.5 mm diff in radius When I ran 60 mm 559 Big Apples on 23 mm rims they measured about 26.25" in diameter (tho' my measuring method was quick and dirty). On Wed, Oct 31, 2012 at 9:47 AM, franklyn <sini...@msn.com> wrote: > I am afraid that Ian is right. I have measured the circumference of my > wife's 700cx28mm wheel and my 650bx42mm (hetre) wheel using the rolling > test diagramed in user manual of every cyclometer, and here are the results: > > 1. 700c wheel with 28mm Clement 28mm tire: 2110mm > 2. 650b wheel with 42mm GB Hetres tire: 2094mm > > The difference is around 1.5cm. If you currently use 170mm or longer crank > arms, you can switch to a 165mm crankset and mitigate the drop by 5mm (or a > whole 1cm if you use 175mm), but the drop is significant. > > I hope that's helpful, > Franklyn > > > On Wednesday, October 31, 2012 8:33:25 AM UTC-7, IanA wrote: >> >> 650b rim diameter is 584mm. 700 is 622mm. Not sure that you'd get even >> 1cm extra height from the difference in tires. You might be dropping the >> BB the best part of 2cm. That's probably pedal strike territory. . >> >> On Tuesday, October 30, 2012 3:48:33 PM UTC-6, ttoshi wrote: >>> >>> I'm thinking about a potential 650b Ram with 42mm Hetres. Apparently >>> the 42 mm 650b would be equivalent in height to a 28 mm 700c tire, so >>> perhaps the BB drop would not be an issue. I'd love to hear if anyone has >>> successfully done this. >>> >>> Thanks, >>> Toshi >>> >>> -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/rbw-owners-bunch/-/H6p6Lo7VORIJ. > > To post to this group, send email to rbw-owners-bunch@googlegroups.com. > To unsubscribe from this group, send email to > rbw-owners-bunch+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/rbw-owners-bunch?hl=en. > -- ------------------------- Patrick Moore, Albuquerque, NM, USA For professional resumes, contact Patrick Moore, ACRW http://resumespecialties.com/index.html ------------------------- -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
